Air feed mechanism for hot air furnaces



Oct. 20, 1931. s. BORDO 1,328,221

AIR FEED MECHANISM FOR HOT AIR FURNACES Filed Nov. 27, 1929 2Sheets-Sheet 1 SAMUEL I. BORDO dmm Oct. 20, 1931.

S. l. BORDO AIR FEED MECHANISM FOR HOT AIR FURNACES Filegl Nov. 27, 19292 Sheets-Sheet 2 UNFTED STATES SAMUEL I. BORDO, OF CLEVELAND, OHIO AIR-FEED MECHANISM FOR HOT AIR FURNACES Application filed November 27, 1929.Serial No. 410,102.

My invention relates to mechanism for im proving the air circulation forhot air furnaces and I do this by forcing the incoming air into theannular space between the wall of the fire pot and the outer casing bysuitable power means, such as a fan driven by electrical power.

It is a special object of my invention to di rect the outside air intothe above annular 19 space by branch pipes connected with an outer mainpipe connected with the power fan, and provide the branch pipes withupwardlydirected tubes extending just above the in tensely-heated firepot, so that the incoming air from this force feed will never be directed upon the lower portion of the fire pot.

it is a further object of my invention to form the said branch pipes oftubular sections pivoted together at their ends to permit adjustment ofthe curved outline of these branches to fit furnaces of different sizes,and of possible different shapes. It is a further object also to makethese sections detachable to vary the ultimate length of the branches.

This invention will hereinafter be fully described in detail,particularly pointed out in the appended claims, and illustrated in theaccompanying drawings, in which- Figure 1 is a side elevation of afurnace with a portion of the outer casing broken away to show theposition of the structure of my improved mechanism in the intermediatespace between the outer casing and fire pot;

Figure 2 is a side elevation of a single section of the feed pipe;

i ure 3 is an elevation of such a section not provided with one of thevertical tubes;

Figure at is a transverse section of the fur nace taken in the planeindicated by the line of Fig. 1;

Figure 5 is a side elevation of my sectional feed pipe unassembled inoperative position, but having the sections swung on their pivots intoalinement;

Figure 6 is a longitudinal section of two connected sections, as shownin the plane indicated by the line 66 of Fig. 5;

Figure 7 is a similar view of a pair of sections bent out of alinement,and

fire pot 13 shown as supporting the combined structure 1% having thesmoke flue 16 and cleanout pipe 15.

My air feed mechanism will comprise a cold air intake pipe 17 which isdesigned to introduce cold air to be heated by the furnace, while in thespace between the casing 11 and the fire pot 13 and thereafter forcedupward into the hot air pipes 12 which lead to the various rooms to beheated. It further comprises an electric blower 18 of a conventionaltype whose power is obtained by suitable connections 19 carryingappropriate current from the usual power source, the incoming airentering at the opening 20 opposite the motor 21, and thence forcedthrough the pipe 17 into a sectional distributing tubular member 22 madeup of sections 23 and 24 pivoted together at 25 and extending around thefire pot from a central section 26 which receives the incoming airdirectly from the pipe 17.

The sections 23 and 24 are duplicated over and over in as great a numberas desirable, depending partly upon the circumference of the fire potand also upon the length of each section. The entire sectional pipetherefore, consists of two flexible members 27 and 28 extending from thesection 26, and each member ending with a section 29 having a closed end31 near the position of the furnace door 30. Each of the sections 23 and24 will ordinarily have a small and a larger end to render it feasibleto telescope the smaller end 32 of one section into the larger end 83 ofthe next, the two sections being held in such telescoped relation bypivot plates 34 having their ends riveted to the outer wall at 35, aswell shown in Fig. 8 of the drawings. These plates 34 are 0 -set, asshown in Figs. 2 and 3, to readily make the connection desired.

The middle section 26 will have bothv ends of equal size to enter thesections 21 of the members 27 and 28. The length of each of the lattermembers may be varied by omitting or adding certain sections.

A serious defect of former air circulating attachments of this generaltype lay in the very general positioning of the discharge device,heretofore thought essential, in the lower portion of the space betweenthe tire pot and the outer casing. It has often been thought advisableto direct the incoming air from the discharge ()1)QI1lI1,Illlillattachment directly against, or closely adjacent to the highly heatedlower end of the fire pot, on the assumption that the incoming air wouldthus be very highly heated it passed up Ward about the furnace and intothe hot air fines. But this con truction it has been found is apt toresult in injury to the walls of the fire pot by the expansion andcontraction resulting from the forcing of the incoming cold air upon theouter surface of these walls, and the varying temperature of such freshair as Well as the varying force of the current depending upon the poweremployed.

-My improvement is therefore, especially designed to provide means forforcing the in coming air from the main discharge member into the spaceabout the fire pot, but at points above the plane to which the burningfuel extends, and at the same time preserving most of the advantagesarising from positioning the main discharge member low in such airspace. I have shown in these drawings a serles of vertical pipes 36which are directly attached to certain of the said pipe sections, suchas those designated by the numeral ii. The lower end of these pipes willbe outwardly flanged, as at 37, to provide a riveted joint with thesection, as shown in Fig. 2. These pipes will be of such length thattheir upper ends 38 which are open, will rise above the larger portionof the fire pot, so that, while the incoming air rising through theseipes will be partially heated before escaping from such open ends, itwill not be directed against the walls of the fire pot.

These pipes 36 may be attached ti, any umber of the sections of mysectional d1 lTllJLlhing member 22, including the end section s 29; andif the several scctimis are imatively short, a given length of the maindistributing member will require a lar or number of sections, and fewerof the ctions will need to be provided with the pipes 36. Forillustrative purposes only I have shown the members 27 and 228 made upof sections *5 and whose alternate sections 23 support no airp;ipes,only the sections 2-1 being thus provided. In any case. the pipe17 will enter the aperture 39 in the casing andv connect directly withthe intermediate section 26 within the air space, and the remainingsections of the members pivoted in alternate arrangement. The entranceaperture 3.) may if necexsary, be positioned other than at thepointdirectly oppo site the door 30, since all of the sections will befed by the main pipe 17, wherever it may enter the casing.

Since the several sections of my distributing member are pivotedtogether, the curve of such member will vary with the adjustment of thesections on each other, and at the same time carrying with them thevertical pipes 36 which will assume the appropriate position about thefire pot, as determined by the position of the main pipe The members 27and 28 need not be arranged in a pronounced curve or are, but mayevidently, be extended in arcs of small radius, or even in asubstantially straight length, as shown in Fig. if an elongated space isto be fitted with such attachment. The varied size and numher ofsections and their pivotal connection, makes possible their assemblagein ohl hotair furna .:es as well a: in new structures.

While I have shown the smaller end of each section 235 ano ll, very muchsmaller than the other, this is to be considered merely a matter ofdegree, the difference in size being such a: to permit swinging of thesections upon. their pivot, as shown in Fig. 7, but the l li'ciewcr in'viI A' should not be too great, so

as to cause too great leakage at the joint. If

however, there is a slight leakage at these joints, other heavy cold airwill rush in at such jointsv and pass upward through the ipes 311. Allor only a few of the sections may be provided with such pipes, and thelatter will usually be shaped of uniform size throughout their length,and will ordinarily have an unobstructed orifice at their upper ends.

Operation: Assuming that the furnace 10 includes the outer casing 11 andthe fire pot l3 properly assembled, and that the tire pot 13 includes alower portion in which the burning fuel is supported and an upperportion receiving smoke and other as well as flames from the fuel, thetwo portioi'is of the fire pot ordiiun'ily connected together as at-11), the blow p p-1* 17 is directed through the casing in the aperture39, and the two members QT and 29 of the harge tube directed oututtrdlyand around the lower portion of the the pot, for as long an are as it isdesired, the pipes 36 extending upwardly from the incmliiers QT and 28just above the plane of the connection -10, the blower 18 is driven bythe motor 21 whereby the outer cold air rushes in through the opening 20and then forced by the blower 18 into the pipe 17, and

thence to the tube The air in the tube 22 and in the pipes $3") is beingheated by adiation from the lower portion of the [ire pot 13, but nodirect air current is forced against the walls of the fire pot, so thatthe latter will not be broken by the sudden rush of air against theintensely heated furnace walls. 7

The air rushing out through the orifices in the ends 38 of the pipes 36,will be heated to a high temperature by its flow through such pipes andsections which are so closely adjacent to the fire pot, but not incontact therewith. From the ends 38, the air will then be forced upwardby the heavier cold air below, and be directed to the several rooms ofthe dwelling by the pipes 12 of the casing. The upper portion of thefire pot 13 will of course, increase the temperature of the warm airfrom the pipes 36, but this part of the fire pot is not likely to beinjured by such air current, since it is above the level of the burningfuel and will not be subject to extreme expansion and contraction.

The members 27 and 28 may well be supported upon standards 41, or by anymeans of holding such members with their attached pipes 36 in properposition in the space about the fire pot. This improved air feedmechanism meets a very serious condition which I have observed inattempting to improve the circulation of the outer air within the casingup through the carrying pipes: It is well known that the speed of theincoming air current can be increased, and has been done by devicessimilar to the blower 18 of my structure, but it has not been heretoforefully appreciated that forcing the air against the fire pot has wreckedsuch fire pots, and that the only means of correcting it in the past,seems to have been to lower the speed of such air current. My improvement therefore, enables the user to increase the incoming air current,without injury to the furnace, however great the speed of the currentmay be, or how intense the heat of the wall of the fire pot may become.By employing my improved structure, changes in the heat in the fuelportion of the fire pot, however sudden, as by operating the drafts,will not endanger the fire pot walls, whether the motor 21 is running athigh or low speed.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is,

1. The combination with a furnace having an air chamber between the firepot and the casing of the furnace, of an air tube positioned in thelower portion of said chamber, hollow pipes connected at their lowerends with such tube and having their open upper ends extending in saidchamber above the level of the lower wall portion of the fire pot, andmechanism outside the said casing for forcing the outer air through anaperture in the casing into the said air tube.

2. The combination with a furnace having an air chamber between the firepot and the outer casing of said furnace, and a sectional air tubepositioned in the lower portion of said chamber of vertical hollow pipesconnected at their lower ends with such tube and having their open upperends extending in said chamber above the lower wall portion said casingfor forcing outerair through an aperture in the casing into. one tionsof the said air tube. a

3. 1 The combination'with a hot air furnace having an air chamberbetween the firepot and an outer casing, a sectional cool airtubepositioned in the lower portion of said air chamber, and vertical hollowpipes connected to certain of the sections of said tube and having theiropen upper ends extending in saidair chamber above the lower Wall por-.

tion of the fire pot, so that air from said tube and pipes will not bedirected against the lower wall portion of the fire pot, of a blowerdevice outside said casing for forcing outside air into the saidsectional tube.

, 4. The combination with a furnace having an air chamber between thefire pot and the outer casing of the furnace, a sectional air tubepositioned in the lower portion of said air chamber the sections of saidair tube be-; ing connected together end to end in pivotal relation sothat the tube may be positioned adjustably in an arc in said chamber,certain of said sections supporting on their upper surface verticalhollow pipes having their lower ends connected with the respectivesections and their open upper ends extending above the base portion ofthe fire pot, so that air from either said tube nor pipes will bedirected against the lower wall of said base, of a tube leading throughan aperture in said casing and connecting in said chamber with one ofsaid sections, and a blower device for forcingioutside air into saidcasing tube.

5. The combination with a furnace having a heating chamber between aninner heating element and an outer surrounding casing, and a sectionalair tube positioned in the lower portion ofsaid chamber, of a blowerdevice for forcing outside air into said sectional tube,and meansattached to said tube for directing air therefrom upwardly in saidchamber into the upper portion of the latter, but out of contact withthe lower portion of said heating element.

6. The combination with a hot air furnace having a heating chamberbetween an inner heating element and an outer surrounding casing, and anair tube positioned in the lower portion of said chamber, of a blowerdevice for forcing outside air into said air tube, and means attached tosaid tube for directing air therefrom upwardly in said chamber into theupper portion of the latter, but out of contact with the lower portionof said heating element.

7. The combination with a hot air furnace having an air chamber betweenthe fire pot and an outer casing, a sectional cool air tube positionedin the lower portion of said air chamber, the sections of said air tubebeing connected together end to end in pivotal relation to permitadjustment of the tube in an of the fire pbt,;a'i1'd mechanism outsidethe.

of the sec-.

4 smash be about said fire pet, of a, blower device outside said casingfor forcing outer air into sectional tube, and spaced tubes: con; nectedat their lower ends with certain 02B saidsaetionsandaentendin upwardlybeyond than level at the intenselyeated base of'the fine-plot, fordirecting from the said sections aim tn the upper portion of saidchamber, but out 05 contact with the said base ofi the pot.

8: The combination with a hot air furnace and its fire pot and a coolair intake pipe, oi useetional aintube supported in the space be-. m thesaid: fire pot and its outer casing,- one- 01 the intermediate sectionsbeing con-. wanted with said intake pipe, and the end sew tionshavingolosed outer ends, a plurality oi nominal having their lower endsattaehod' to certain of said sections, and their an upper ends extendingabove the level of most intensely-heated portion of the fire EM, wherebythe air in said pipes will be noted by radiation from the base of thefire but will' not be directed against the wall 0! thelatter, and ablower arran ed for connod-ion with the receiving end 0 said intake P 9:Thecombination with a hot air furnace haminga heating chamber between aninner heating element and an outer surrounding easih and a sectional airtube positioned in the lower portion of said chamber, tubular mechanismoutside the said casing leading through an aperture in the casing intoone of the air tube sections, and means attached to certain of saidsections for directing air therefrom upwardly into the upper portion ofsaid chamber, but out of contact with the lower portion of the saidheating element.

Iii-witness whereof I have hereunto set my hand this 26th day ofNovember, A. D. 1929.

SAMUEL I. BORDO.

